Color photography



Jne 2, 19.31. 1..'1'. TRoLANb 1,808,584

coLoR PHOTQGR'APHX Filed Sept. 9, 1921 .mantenne z, 1931 uNf'rlezDSTATES PATENTOFFICE l N LEONAEDT. TBOEAND, or MALDEN, MASSACHUSETTS,ASSIGNOE To OOMSTOOK a WES- COTT, TNO., OE BOSTON, MASSACHUSETTS, aCORPORATION or MASSACHUSETTS COLOR THOTOGRAPHY applicati@ ineavseptember 9, 111m. serial No. 499,425.HE|

This invention relates to photographic films vand the production andreproduction of same, particularly in color photography, whether forstill or motionl pictures, this application being in part a continuationof my prior application Serial No. 377 ,7 55, filed April 3o, 1920.

A principal, object of the invention is simultaneously to produce at aSingle ex- ?.0 posure, a plurality of separate superposed complement-alimages on a single film adapted to beused in an ordinary still pictureor cinematographic camera without substantial modification ofthe latter.f Other objects of the invention are to simplify the art of producingcolor pictures, to reduce the time and cost required to produce suchpictures, to afford al simple automatic way ofobtaining accurate ratiosof exposure between complemental images, to obtaincomplemental imageswhichare in accurate registry throughout `their entire area and Vwhichmay be reproduced .with automatic registry, to secure good definition,to minimize halation and generally to improve the ,art of lcolorphotography.

In order to clarify the subsequent description of the invention thefollowing 'definitions are here inserted.v Unless otherwise specificallylimited the term photographic film is herein employed generically toin-y clude all photographic records or recording articles or devices,whether the emulsion is supported upon celluloid `or other support or isself-supporting, and Whether the film is adapted for either still'ormotion pictures.

. The term emulsion is used generlcally to'v connote either a trueemulsion or other composition' which is sensitive to light. The 4entrant side of the emulsion is -the .side

emulsion, whether or not 1t be next .t0 the celluloid or other support,and the emergent l dominates. The warmercolors are t Osev nearer theredend ofthe spectrum and the colder colors. vare' those nearer the violetthrough which the exposing light 'enters' the.

.end of the Spectrum. The term complemental images is used to designateimages representative of different color aspects of an object field,which when combined by printing, projection or otherwise, will yield amore or lessaccurate color reproduction of the object field, the imagesthemselves not necessarily being colored, and the colors which theimages represent not necessarily being exactly complementary. The termdeveloped images connotes images which have been developed whether .ornot they have been subsequently bleached. The term transparent imagemeans an image which is substantially transparent to light of one ormore colors 'though not necessarily to all colors.

The invention involves a photographic film having an emulsion which 1smore sensi-l tive to -light of a predetermined color throughout a partof its depth than throughout another part of its depth, or which ispredominantly sensitive to one color only throughout a part of itsdepth, or whose sensitiveness to light is adjusted differently 715l fordiierent colors-throughout atleast a part of its depth, or preferablywhich possesses lall of these characteristics. The variation of thecolor sensitiveness of the emulsion ma be gradual or by steps or Stages.Av gray ual variation may be obtained by bathing the film in a suitabledye and ermitting the dye to penetrate to successive 'epths in graduallydecreasing measureor by thus sensitizing one side of the emulsion withone dye and similarly sensitizing the'other side with.

another dye. A step by Step variation may be obtained by building up theemulsion as a succession of layers predominantly sensitive to dierentcolors. However, there are many advantages in forming the emulsionin asingle layerand I therefore deem it highlfy desirable nottoform theemulsion in the orm of separate superposed coatings. By exposing thefilm to light from. a` multi-l colored object field an imagecorresponding to one color aspectfof the field is formed throughoutv thelwholel or a part of the depth of the emulsion which vis -predominantlysensitive ton that color and an image correspo'11d4-- 100 sol . ing toanother color aspect of the field is formed throughout the whole or apart of the depth of the emulsion which is sensitive to `the other colorand so on depending upon the number of complemental images comprised 1neach set of lmages. In two-color work a Ablue-green record maybeformedi'n one de th and a red record in another depth. A terthe'images are thus formed they may be treated and reproduced in variouswa s, examples of which will hereinafter be scribed. f y

In order to restrict the light reaching the emergent side of theemulsion to the color to which the emergent sidejis speciallysensitized, the whole emulsion, or at least a portion -toward theentrant side, is preferably dyed or otherwise colored so as to obstructlight of other colors and to transmit light ofy the color to which theemergent side is sensitized.` This serves to restrict the image orimages of the other color or colors to the en- `trantside of theemulsion. y In -two-color work, e. g., the emergent side may besensitized to the warmer colors and the emulsion may be dyed with a dyewhich will transmit the warmer colors and obstruct the colder colors.When the film is exposed an'- image of the warmer colors will beformedon the emergent side andan image of the colder colors will be formed onthe entrant side. While the light of warmer color passing through. theentrant side may expose the entrant side to some extent, and while someof the colder light may penetrate to the emerent side, these ee'cts canbe rendered neggible as will hereinafter appear.

For-certain uses of the film it is desirable that one of the images b emore intense than the other or others. Forexample, according to onemethod of using the film hereinafter described one image should be somuch more intense than the other or others that in reproducing theimages b passing flight through all of the imagesyofea'ch compDlementalset in series the vimage or images other than the intense image will benegligible for practical purposesv compared with the intense image. Thismay be accomplished in various Ways as for example by treating orpreparing t h e emulsion, or at least that part of the emulslon intendedto bear the less intense image, so as to render theless intense imagerelatively flat (i. e. having a relatively low gamma). The dyehereinbefore referred to which obstruct's the light of the colorrepresented by the -entrant image also performs this'function, althoughin order to obtain a pronounced flattening effect the dye shouldordinarily be more intensely absorptive vthan is necessary to preventthe passing of the light of the particular color to the` I emergent side of the film.

When employing certainof the methods to which my improvedfilm is adapteditis de- 'sirable (although not always necessary) that the portlons ofthe light-sensitive strata bearing the .respective superposedcomplemental images be separated by 'a free gelatine layer.

For example, if it is desired to separate the images produced in theportions which vare predominantly sensitive to different colors or if itisdesired to impregnate or otherwise treat the portion bearing one imagewlt'hout affecting the other image or images, as Aherevindescribed, itis advantageous to havev the portions somewhat separated.

For good results in two-color work the negative filmshould have thefollowing characteristics. The entrant stratum of the "emulsion shouldbe insensitive or relatively insensitive to orange, red and possiblyyellow l light, thatv is, light having wave lengths greater thanapproximately 590 ma. This stratum should be sensitive to blue,bluegreen, and preferably green and yellowgreen light. The same stratumshould be of such color as strongly to absorb substantially all of thespectrum to which it is sensitive. The exact degree of this absorptionis determined by the method of subsequent treatment and by the effectsto be produced in the finished pictures, but inA general it should bemany times (e. g. of the order of one hundred times) greater than thatwhich results from ordinary impregnation with dyes for the purpose of'green sensitizing or orthochromatizing the emulsion. The emergent.'stratum'of the emulsion should be sensitive to orange, red, andpossibly yellow light. In general it is immaterial whether this stratumis also sensitive to other rays of the spectrum lsince the other raysare absorbed before reaching this stratum.

One method of producing a the-above characteristics involves the use ofa recoated film. The first coating of emulsion may have ordinary silverbromide sensitivity, being responsive to ultra-violet, violet, blue andblue-green rays only. The film n may then be recoated (on the same side)vwith an ordinary panchromatic emulsion which is responsive topractically all the rays of the spectrum if previously 4sensitized togreen, yellow and red with isfocyanine'd es as orthochrome T (colorindex 807) an pinacyanol (color index 808) as is customary in makingpanchromatic emulsion. This recoated film is then bathed in a dyeadapted to impregnate the emulsion strongly and to make it stronglyabsorptive of blue, blue-green, green and yellow-green rays, andpreferably at the same time to sensitive the emulsion throu vhout. gto'green, yellow-green and possi ly yellow rays. Instead of incorporatingthe dye by bathing it may be mixed intothe emulsion of the firstcoating. before the coating is applied to 4the Celluloid. This permits amore reliable determination of the concentration of the dyethe-emulsiombut film having sion.

in vgeneral does notaford such a fast emul- Another method of producinga lm hav.-y

ingA the above characteristics 1nvolves the The dye for Vstaining thenegative stock as aforesaid should have the following characteristics.It should be capable of impregnating gelatinev strongly. It shouldabsorb blue, blue-green, green and yellow-green rays. It shouldsensitize silver bromide to vgreen and yellow-green rays. It should notinterfere with or destroy the action of the isocyanine orred-sensitizing dye, and it should Wash out of the gelatine afterdevelopment and fixation with fair facility.

I have found that alkaline fluoresceinates and their halogenderivatives, such as uranine `(color index 7 66),-eosine (color index768),

' sodium di-bromo-fluorescein, erythrosin (colorindex 772-773), etc.,are completely with- :out desensitizing action and otherwise fullll theaforesaid requirements. Other suitfabe dyes are filter yellow Kandkodachrome re v A highly satisfactory dye for average conditions is amixture in aqueous or aqueousalcoholic solution of uranine (sodium llue-'oresceinate) and ordinary eosine (sodium tetrabromofluoresceinate),`although this mixture permits a certain amount of yellow, in additiontoorange and red, to. penetrate to the second stratum.` `There it isdesired to eliminate the yellow rays from the second stratum and torender the first layer more sensitive to these rays, as'in takingoutdoor scenes where the green of vegetation is involved, better resultsmay be obtained by adding to the above mixture xylene red B (Schultz No.579). The absorption band of xylene red B ends labruptly at about 600 maandthe sensitizing action extends approximately to 610 mn. This dye hasall .the other desired properties; s

In bathing a recoate'd film such, as above decribed the dye may comprise90 parts water, 10 partsalcohol, 1 part of said uranine, and 0.2 part ofsaid cosine; or, when employing said xvlene-red, 90 parts water, 10

parts alcohol, 0.8 part of said uranine, 0.08.

part of said eosine, and 0.05 part of said xylene red. To insureadequate and uniform penetration of the dye to the first coatingl thefilm is preferably bathed aplroxirlaelydone an rie at hour atapproximately 65 approximately F.

In the accompanying figures, i Figure 1 is a' diagrammatic view form ofmy improved film;

Figure 2 is a diagrammatic view of one way i of roducing the imagesthereon;

`igure 3 1s a diagrammatic view of one wayl of reproducing same; and iFlgure 4 is a dlagrannnatic view of the application of theinventiontothe production of threel color pictures.

In Figure l I have illustrated ferred embodiment of the inventionwherein F represents' a support of celluloid or other suitable materialand E represents the emul-y sion which may be of the kind predominantlysensitive to the colder colors.

out the cross-hatched portion W. This may be accomplished bv bathingthev film' in a sensitizer (e. g., said pinacyanol dissolved in alcoholand water) the sensitizer being per-V mitted to penetrate, at least insubstantial measure, only throughout a .portion of the depth of theemulsion. The portion W of the emulsion is thus renderedsensitiv'e tothe.

The emulsion is sensitized to the Warmer colors through-V one preposedthrough the back (i. e., through the celluloidhas is essential for somepurposes,

theemulsion maybe -dyed orange as, e. g., byV

use of dyes previously specified, including one such as said filteryellowv K which absorbs violet and vultra, violet, thus rendering theemulsion predominantly transmissive to the warmer colors. Upon exposingthe film to -a camera, proiection printer or the like, and

F represents the Celluloid, thusv illustrating my preferred method .ofexposing through After the y the celluloid or yother support, filmhasbeen exposed it is developdfor the time required to give the propergradations of the variousl areas of the. images or each set relative toeach other and ofthe respec` tive sets relative-to each other.

Instead of using the entire spectrum of col- Zors and dividingthe entirei ght from the 11e a colored obiect or' image field through the iportions as described, the light may be passed .ponent to pass to theemergent side.

through a color filter adapted to absorb a part of the spectrum beforethe light reaches the film, in which case a different dye is used in theemulsion to divide the used portion of the spectrum in the desiredproportions.

For example, the exposing light may be passed through a yellow filter X(Fig.l 2) which absorbs the blue end of the spectrum (e. g. violet andultra violet) and an acid scarlet dye (e. g. said eosin in combinationwith said uranine in the proportions already stated) may be used in theemulsion to rcstrict thegreen component of light to the entrantside andpermit the red or orange com- Inasf much as the filter has substantiallyno absorbing action on the rays to which the emergent side is sensitive,exposure balance between the complemental images may be regulated by lchanging the filter. v

Instead of using a color filter the 'Celluloid film may be impregnatedwith a yellow dye having the desired absorption, for example phosphene;or the dye maybe applied, as a `constituent of gelatine ,or othertransparent coating on the back of the Celluloid after the manner of thewell-known non-curlingcoating. Another method is to employ an ex'"tremely heavy staining of the emulsion itself with a vdye very stronglyabsorbing ultra violet and violet, as for example said filter yellow Kor Eastmanyellow (color index 640) as already indicated.

Development of the exposed film should kbe bythe time-temperaturemethod, since the ratio between the red and green records' in the twostrataof the film depends not only upon exposurevbut toa considerabledegree upon development, both as regards the apparent inertia of therecords and their apparent contrast. It isdesirable to soak the film incold water for a few minutes before placing it in the developer; thiscauses a preliminary swelling of the gelatine and enables development tobegin throughout the film more near- 1y simultaneously than wouldotherwise be the case.' Y

The green record canA often be improved inspeed and in the form of itscharacteristic Curve by slightly fogging it previous to development byexposure of the film through' the back to rays which'are stronglyabsorbed Owing to the fact that the developer-acting upon the greenrecord image in the first stratum'must firstpenetrate the second stratumthere is a strong: tendency for itto become'lol cally exhausted by itsreaction with the red record image. This has the effect of producingvalocal reduction ofdevelopment of the green record image Aunderneathrelatively high densities of the red record image, Awith acorrespondingly bad effect upon the final color rendering. In order toreduce this socalled exhaustion 'effect to a minimum it is desirable touse a developer possessing'a high diHusion tendenc and a relatively lowreduction potential.v uch a developer is hydroquinone combined with analkaline carbonate (e. g. in the ratio of one part hydroquinone to tenparts of carbonate in one hundred parts of water). A small amount ofmetol (color index 875) may also b e added to render the developmentmore rapid.

After development the negative is `fixed in a plain hypo fixing bath, isthen washed until the dye has substantially disappeared, and is thendried in any suitable manner.

The following are examples of the Vuses tol which my new film isapplicable after it is developed and otherwise suitably treated,two-color films being referred to for the purpose of illustration.

The images on the opposite sides of the emulsion may be separatelyprinted by reflecl 'opague white material may be provided in theemulsion as for example in the form ofv silver bromide not lfixed out.

If one of the complemental images (the image representative of thewarmer color in the foregoingl example) is made much more intense thanthe other, e. g. ten times as intense, this image m'ay be reproduced byprojecting light through both images of a coml plemental set, theintense image predominating to such extent that the combined effect of vall the images is virtually that of the intense image. n After theintense image has been reproduced, or in thecase of a motion picturefilm after the series of intense images have been reproduced, theintense image or'images may be rendered ineffective, as e. g; by bodilyvremoval after which the less intense im'age may be reproduced either insuperposition with the intense-image or otherwise. When the intenseimage is on the outside of the film as illustrated, it may bel removedby bleaching the film in a solution which produces both images inhardened gelatine and thenetching the film in hot water about l120" F.)which dissolves the soft gelatine betweenfthe images and allows theintense image tofloat ofil but leaves the other image adhering to thecelluloid or other support.

, The bleaching solution may comprise approximately 100 parts water, 2parts chromic acid, 5 parts sodium chloride, and 0.1 part sodiumsulphite.. Before placing the film in the solutionit is preferablysoaked in cold 'water until the gelatine has swelled to a proximately anequilibrium' condition'. T e solution converts the silver and at thesame time hardens the gelatine in the :form of the iso ' 1,sos,ss4

to break up in the etching process. These` two tendencies can beremedied by a slight chemical reduction of the bleach, which isaccomplished by the additionof sodium sulphite or other reducer. Thereduced bleach yields a more pronounced and more coherent relief.

However, an excessive bleach reduction must be avoided, since a greatlyreducedl bleach, especially if diluted or slow acting, has the peculiar.effect of-impressing upon the green record relief an image componentwhich is proportional tothe superposed red recort In other words aositive o f-the red recor is added to or combined with the green record,for which reason I have called -this phenomenon the bleach-.positiveeffect.` This effect can be substantially avoided by` employing arapidly acting bleach, such as above specified, inasmuch as the effectdepends upon the diffusion of gelatine-hardening substances from the redrecord into the stratum occupied by the green record.v y

The bleach-positive effect is in general the reverse of the exhaustioneffect; consequently b regulating the bleach-positive effect as a oveoutlined it lmay be utilized approximately to neutralize the'exhaustioneffect'.

After the image remaining on the .film is thoroughly etche with the hotwater to clear up the relief,'the silver salts arefixed out in plainhypo, the hypo being subsequentlyremoved by washing, andthe film is thenpreferably dried before further treatment.

The adheringimage is then intensified optically after which it may bereadily printed. The intensification may be effected by stainving thegelatine relief with a dye which strongly absorbs the actinic rays ofthe spectrum. The dye should have greatafiinity for gelatine in orderlto produce a heavy staining of thel relatively .thin`relief; anditshould wash out slowly so that the superficial dye adhering to thesurface of the film may be rinsed off without unduly bleeding the film.-

A satisfactory dye for the purpose is croceine scarlet in'a 3 per cent.solution with 5 per cent. acetic acid, thisdye affording anenormousintensiflcation of the original'image.' The time of immersion ofthe film in this solution determines the degree of printing contrastwhich it attains, the contrast continuing to increase slowly over aperiod -as 'long as twelve hours. Ordinarily. an immersion of about20'minutes suilices when employing a dye of the above composition. Whenproperl contrast is attained the film is removed from the dye, rinsedand dried rapidly, after which itis ready for printing.

Instead of forming one of the complemental images with negligiblecontrast and then intensifying it after the more intense -image has beenreproduced, I have discovered various subtraction methods ofreproduction 4 which do not depend upon this difference in contrast.When the contrast of the entrant image need not be kept down to anegligible amount, the quantity of dye with which the emulsion is vdyedmay be greatly reduced, thereby increasing the speed of exposure.

The followingis one substraction method of reproduction'such as referredto above. A positive is made byprint'ing through both negative records.The exposure and characteristiccurve (depending upon the exposure andthe emulsion employed) of the positive should be such as tov render itsubstantially an exact black-and-white complement o-f the originalnegative, so that when the two are supe posed in registry no picture,either positive or negative, is visible.

The original negative may then be treated .to remove the red record bythe same or equivalent method as described above for this pury pose. Itis desirable, however, to retain the silver of the green-record image inits original form and densities. This can be accomplished if thedevelopment of the film is initially by means of a pyro formula, whichwill give hardening of the gelatine in the formy of the imagesimultaneously with development thereof. Any pyro developer containinglittle or no sulphite preservative may be employed for this purpose. Thegreen-rec-` ord image thus separated is now superposed in register uponthe complement of the total record which was previously obtained. Thisproduces a positive which is substantially thatv of ,the red recordalone. From this positive is printed a negative which corresponds to theoriginal red-record negative.

ftradistinction to -a subtraction of the exposures which would result inusing interpenetrating images formed by exposing the same emulsionstratum to the respective color components of light. By subtractingdensities instead of exposures .the component image A resulting from thesubtraction process has far more accurate density gradations than whensubtracting exposures.

Among the other possible methods of separatly'reproducing the superposedcomplemental negatives there are various rede yelopment methods which donot necessitate 'making one of the-negatives extremely ii'at. One suchmethod involves converting both negatives into unexposed light-sensitivesilver salt, exposing onenegative without substantially exposing theother negative, de `veloping the exposed negative, fixing out the vsilver salt of theunexposed and undeveloped Aeo negative with hypo torender the gelatine transparent, printing the redeveloped image,l thenetching. olf the printed image leaving the transparent image adhering tothe Celluloid in the form of a relief, and then staining and printingthe relief. The conversion of both'images into light-sensitive silversalt may be eifected by bleaching in the' dark with a solution of copperbromide. One negative may be exposed withoutbsubstantially exposing theIother by heavily dyeing the emulsion, thereby absorbing the lightbefore it reaches the secondy negative, the dye originally incorporatedin the emulsion before the original exposure ordinarily being suiicientfor this purpose. In redeveloping the reexposed negative a low potentialdeveloper` such as hydroquinone is recommended. The negative which isnotreexposed and rcdeveloped may be converted into a transparent reliefin either yof the 36 aforesaid ways, viz., by using a pyro development.-The transparent relief preferably represents the green aspect of theobject field. This mode of reproduction I call the invisible imagemethod.

vAn alternative method of separating the component negative images inpreparing the positive is to transform each of these images into animage in pure -dye or other coloring 4matter, each'image absorbingexclusively cervtain spectral rays or colors. F or' example, in the caseof a two-color record the cold color image might be converted into animage -in yellow or minus-blue dye and the warm color image into Aanimage in magenta or minusgreen dye or other coloring matter. There arevarious ways in which this could be acf complished. For example, bothimages may be converted into a dye suchas Metanil yellow; (color index138,) which when acted upon by an acid becomes magenta in color. A smallamount of acid may then be diffused into the 'film so that the imagenext to the su'i'-, face .isl converted into magenta while the other4image is not sensibly "adected Another method 4is to convert the imagenext to the surface directly into a magenta dye image.

p image. p ,Y

-One'such method consists 1n, converting tives. may be made muchshorter.

both negatives into unexposed light-sensitive i silver salt, exposingone negative without sub'- stantially exposing'the other negative,andployed as a mordanting base for a dye of the appropriatecolor whichis not absorbed by the metallic silver image. The latter may be coloredthe desired color by any well-known toning process which does not actupon the' silver salt or dye of the other negative. By4

employing. a bleachv which will convert the silver into silver iodide in-the aforesaid bleaching loperation a considerable variety of dyes areavailable in the mordanting process. For example safranine' may beemployed to reduce a magenta color. In the toning process a yellow imagemay be produced by em ploying a titanium salt. The negatives thusdiHerently colored may be separately printed by using lights ofdifferent colors, the -light used in printing each negative beingabsorbed strongly by.tliatnegative and weakly, at all, by the other imge.

It is clear that when this conversion of the images into respectivelydifferent colors, as

above specified, has been accomplished, if bluel light is employed toprint through the combined lilm, only thev yellow or minus-blue coloredimage will be printed, since the blue light will not be absorbed'by1the' magenta image. Qn the other hand, if green light is employed, only.the magenta lor minus-green image will be printed, since the greenlight will not be absorbed by the yellow image. In this way it will bepossible to effect an optical separation of the two images withoutremoving either of them from the iilm and also without involving anyappreciable adulteration of one image by traces of the other.

"In the last aforesaid method the original exposure need not be madethrough the celluloid or other support inasmuch as it is not necessaryphysically to separate the nega- Consequently the original exposure Itis evident that a negativel film of the character above described maybeused to print both negative records simultaneously if a positive filmhaving the general struc ture of the ne ative film which is described inthese speci cations is employed. In this case the two strata ofthepositive film may be rendered sensitive to blue 'and green raysrespectively, the entrant side of the positive emulsion being sensitiveonly to the blue whilethe emergent side-is sensitive also to the green.The entire emulsion is stained with a dye which. absorbs blue, so thatonly los the green rays reach the emergent side, while only the bluerayscan act on the entrant side. If the multiple colored negative isused to print on such a positive with combined blue` and green light, 1.e. yellow or possibly white,

the cold record image of the ne ative will be printed on the entrantside o the positive emulsion andthe warm record image on the emergentside of the` latter. This method of printing is illustrated in Fig. 3wherein Fn represents the celluloid baseof the negative film, Cn' and Wnthe strata of the negative emulsion bearing the cold and warm imagesrespectively, Pp'the Celluloid support of the positive film, and Cp andWp the strata of the positive emulsion intended to receive the positiveimages respectively. The strata Cn and Wn may, e. g. be dyed with ablue-absorbing (yellow) dye and with a green-absorbing (magenta) dyerespectively, in which case the strata Cp and Wp maybe receptive to blueand green colors respectively. The arrowat the top of the figureindicates the direction of the printing light, which in this example ispreferablyv formed of blue and green components.

Selective stainingof the two separated positive images thus obtained maythen be carried out so that the positive from the cold color record isconverted into a color complementary to that' which originally producedthe record in the negative, with a corresponding conversion of the printfrom thewarm color record.

From the foregoing it will be evident that inthe more limited aspect ofthe invention a cardinal feature consists in formi-ngl the film so thatthe face of the emulsion next to the celluloidor'other-support is theentrant face, instead of the emergent face'as is usual, and so that themore intense image is formed on the emergent side of the emulsion.

' While the invention has been described with particular reference totwo-color work it is also applicable to the production of pictures witha greater number of color compo-- nents, one application-to three-colorwork being illustrated in Fig. 4,' where two films, each with its owncelluloid base, are employed with their emulsion surfaces -in contact.

One of these films may be similar in struc:

ture 'to the one shown in'Fig. l, (differing ordinary panchromatic film.Thus in Fi 4 F represents the Celluloid of the first lm carrying anemulsion .E theinner stratumA C of which is sensitive to cold color orcolors e. g. violet, blue, and blue-green, and the outer stratum ofwhich is sensitive to warmer Acolor or colors, e. g. green andyellow-green.

The outer stratum may or may notbe sensitive to the colder colors.

The Celluloid of the secondfilm is designated F and carries an emulsionH which is sensitive to still warmer color or colors, e. g. yellow,orange and red. Eithei` the inner stratum C or both strata C and W areimpregnated with a dye which rapidly absorbs the colors to whlch theinner stratum is sensitive but which does not absorb the colors to whichthe outer stratum is sensitive. If the stratum H. is also sensitivetogreen and yellow-green a filterabsorptive of these colors may beprovided between the two films, which filter ma be in the form of entireemulsion E may be dyed With tartrazine and the outer surface of thisemulsion may be further dyed with Congo .red (colorv index 370) or rosebengale (color index 77 7- 779). The emulsion H may be sensitizedthroughout with pinacyanoL By using a direct cotton dye, such as Congored for example, the dye is confined to a very thinl stratum at thesurfaceA of the emulsion.

With these films in contact (instead ofv slightly separatedas shown inFig. 4 they are, exposed from the side indicated y the arrow. Theviolet, blue and blue-green rays n expose stratum C and are absorbedthereby so that none of them reach the other strata. The green .andyellow-green rays expose stratum W. And the yellow, orange and red irays expose emulsion H. The latent images in strata C and W are treatedand reproduced asdescribed above in connection with" the'two stratainthe two-color processes and the image in emulsionl H may be developedand printed in the ordinary way, it being understood that the threepositives are'suit:

ably colored to give the desired color effect y when combined.

The vpresent invention aords many advantages over prior methods ofmaking color photographs, viz:

The methods herein `described have vthe obvious advantage over thetaking of separation negatives by successive exposures in that both ofthe negative records must necessarily record the same time phase of theobject so that color fringes are impossible. Thesingle exposure alsonaturally involves fewer operations than the taking of two successiveexposures, besides consuming less'time.

The requirement of simultaneous exposure on'the two-color ele-mentscould of course be met byy meansof a specialcamera, butthe sity of thisvery expensive method since it is ap licable to'any'ordinary camera.

he present invention is readily applicable to roll-film cartridge o rfilm-pack cameras, and does not involve any different manipulation thanblack-and-white film, exceptas to length of exposure and. possibly theuse of a color filter although the filter is not essen- ,presentinvention dispenses with` the necesv The A'development of the negativesis similar to the development of bl'ack-and-white negative for eachfinished positive instead of two or more detached component negatives asin other `prior processes.

y When reproducing one of the complemental negatives by transforming itinto a gelatine relief and lthen dyeing the relief the contrast of theposit-ive printed .therefroml can be Well controlled by regulating theamount of dye incorporated in the relief,

thereby accurately balancing thecontrasts of the two positives againsteachother.

One of the greatest difficulties in securing satisfactory colorseparation records lies in balancing the exposures. According to thisinvention exposure balance 'is practically built into Athe Vnegativefilm which has been properly manufactured, so that errors on this pointcannot be IIliade by the operator.

The single iilm feature of the presentmethod permits automaticattainment of register between the two color components of v thepositive, provided proper devices are employed. For example, theoriginal negative and the positive blanks to be printed -upon may besimilarly punched and, in printing, these punchings may be held inregis'er by fitting both lillms over pins so placed in the printingframe as to fit the original perforations. Since the negative isgeometrically identical inthe printing of both color componentpositives, the application of the above method insures that bothpositive lilms may then be registered with respect to each other (or inthe case of imbibition technique with' respect to a third element ortransfer blank) by use of the same perforations. If the mechanicallfeatures of this method are accurately adjusted this insures registervof the final color images without placing any re-l liance on the eyeso'r mechanical skill of the operator.

Another important advantage of the presv ent invention lconsists in thatthe emulsions for the respective complemental images are integrallyjoined together so that there-are no surfaces ,of separation to scatterthe exposing light and produce halation.

For the purpose of simplifying and clarifying the description I have inmany` instances rferredto the images being reproduced as negatives andthe imagesl being printed as positives but it is to be understood thatthe invention is likewise applicable to the production of negatives frompositives if such reverse procedure is desired for any purpose.

I claim:

1. '-A -sensitized element foruse in color 'I photography comprising anemulsion which is sensitive to complemental colors at difl'erent depthsrespectively.

2. A sensitlzedelement for luse in color photography comprising anemulsion whichv is sensitive to complemental colors at different depths,the first sensitive depth being coats-4 substantially insensitive to.lthe complemental color to which a succeeding depth is sensitive.

3. A sensitized element for-use in color photography comprising atransparent support carrying an emulsion which is sensitive to comlemental colors in different -strata respectively, the sensitivity towarmer colors progressively increasing from the support outwardly.

4. A sensitized element for use in color photography comprising anemulsion which is sensitive to complemental colors at differentdepthsthe irst sensitive depth being substantially ab-sorptive of thecomplemental color to which it is sensitive.

5. A sensitized element for use in color photography comprising anemulsion which 1s sensltive to complemental colors at diferent depths,the first sensitive depth being substantially absorptive of thevcomplemental color to which it is sensitive, and being sub- Itocomplemental. colors in different strata respectively, the sensitivityIto warmer colors progressively increasing from 'the support toutwardly, and the inner stratum being substantially insensitive to thecomplemental color to which a succeedingstratum is sensitive.

8. Al sensitized element for use in color photography, comprising atransparent supp'ort carrying an emulsion which is sensitive tocomplemental colors in different strata respectively, the sensitivity towarmer colors progressively increasing from the support outwardly,.theinner stratum being substany tially absorptive of the color to which itis sensitive and being substantially'k insensitive to the complementalcolor to which a succeeding stratum is sensitive.

9. A sensitized element foruse 'in color photography comprising anemulsion having a pluralityof different strata'fast together insuperposition, theJ differentstrata being sensitive to complementalcolors' respectively.- photography comprising an emulsion having I 10. Asensitized element for use in color a plurality of different strata"fast together. in superposition, the 'different strata being sensitiveto complemental colors respectively, and at least one stratum beingsubstantially 'insensitive to the complemental color which a succeedingstratum is sensitive.

11. A sensitized element for use in color photography comprising anemulsion having a plurality of different strata fast together insuperposition, the different strata being sensitive to complementalcolors respectively, and the lirst stratum being substantiallyabsorptive of the color to which it is sensitive.

12. A sensitive element for use in color photography comprisinganemulsion which is sensitive to different colors at different depths, thefirst sensitive depth being sub-I stantially absorptive of the color towhich it is sensitive. l

13. A sensitive element for use in color vphotography comprising anemulsion which is sensitive to one color on its emergent side and on itsentrant side is both sensitive and relatively opaque to another color.

14. A sensitized element for usein color photography comprising atransparent support carrying an emulsion which is sensitive to differentcolors in different strata respectively, the sensitivity to warmercolors progressively increasing from the support outwardly, and theinner stratum being substantially absorptive of the color to which it issensitive.

15. A sensitized element for use in color photography comprising atransparent supp-ort carrying an emulsion which is sensitive to.different `colors in diii'erent strata respectively, the sensitivity towarmer colors progressively increasing from the support outwardly, andthe inner stratum being substantially.` insensitive to a color to whicha succeeding stratum is sensitive. y

16. A sensitized element for use in color photography comprising atransparent support ycarrying an emulsion which is sensitive todi'er'ent colors in different strata respectively, the sensitivity towarmer colors progressively increasingv from the support outwardly, theinner stratum being substantial- '.ly absorptive of the color to whichit is sensitive and being substantially insensitive to a color to whicha succeeding stratum is sensitive.

17. A sensitized element for use in color photographyA comprising anemulsion hav-wv ing a plurality of diierent strata fast together insuperposition, the diiere'nt strata Ibeing sensitive to differentcolors'and vone stratum being substantially absorptive of the color'towhich it is sensitive, the vlatter stratum being nearer the entrant sideof the emulsion than another stratum.

1 8. A sensitized element for use in color photography comprising anemulsion hav ing a plurality of- `diierent strata 'fast totive to thecolor to which a succeeding v depths, one depth being sensitive to'reddish color and a depthl in advance thereof being both sensitive andsubstantially opaque to a colder color. y

. 20. A sensitive element for use incolor photography comprising anemulsion which is sensitive to different colors in diierent strata,vanouterstratum being sensitive tp a reddish colorv and an inner stratumbelng both sensitive and substantially opaque toa colder color.

21. Asensitive element for usein color hotography com rising an emulsionwhic is sensitive to di erent colors in diierent strata, an outerstratum beingsensitiveto a reddish color and an inner stratum being bothsensitive and substantially opaque to a colder color, and the latterstratum being substantially insensitive to the reddish color.

22. A- vsensitive element for use in color photography comprising anemulsion which is sensitive to a reddish color on itsA emergent side andwhich is both sensitive and substantially o aque to a greenish color onits entrant si e.

23. A sensitive element for use in color photography comprising anemulsion which is sensitive to di erent colors in different strata, anouter stratum being sensitive to a reddish'oolor and an inner stratumbeing both sensitive and substantially opaqueto a greenish color.

V24. A sensitized element for use in color photography com rising anemulsionhaving a plurality o diiferent strata fast together insuperposition, one stratum being sensitive to a reddish lcolor andanother stratum in advance thereof being both sensi'-l color.

25. A sensitized element for use in color photographytcomprising 'anemulsion 'have lng aplura y of rdifferent strata p fast together insuperposition, one stratum being sensitive to a reddish color andanother stratum in advance' thereof being both sensitive andsubstantiallyopaque to a greenish color. f

26. A sensitive element for use in color photography comprising anemulsion having a layer sensitive to red and a layer both sensitive andsubstantially 'opaque to green.

27; A -sensitive element for use in color photography comprising anemulsion having a layer sensitive to red anda layer both sensitive andsubstantially opaque to green, and also substantially insensitive tored.

28. .A sensitive element for use in color pho.. tpgraphy comprising atransparent support carrylng lan emulsion which is sensitive'I todifferent colors in different strata, lan outer stratum being sensitiveto red and an inner stratumv being both sensitive and substantiallyopaque to green.

29. A sensitive element for use in color photography comprising atransparent support carrying an emulsion which is sensitlve to dlfferentcolors 1n different strata, an

outer` 'stratum being sensitive to red and an inner stratum being bothsensitive and substantlally opaque to green, and also substantiallyinsensitive to red.

` stratum being sensitive to red and orange and an inner stratum beingboth sensitive and substantially opaque to green and blue-green.

32. A- sensitive element for use in color photography comprising a layerof emulsion sensitized to reddish light and a layer of emulsion dyedWithxylene red.

33. A sensitive element for use in color photography comprising a layerof emulsion sensitized to reddish-light and a layer ofemulsion dyed withuranine and eosine.

34. A sensitive yelement for use in color photography comprising a layerof emulsion sensitized to reddish light and a layer of emulsion dyedwith uranine, eosine and xylene red.

` 35. A sensitive element for use in color photography comprising` alayer ofl emulsion :sensitized to reddish light and a superposed ylayerof emulsion dyed with a solution con- -taining approximately one-tenthto twotenths per cent. eosine and at least approximately .five times asmuch uranine. v

36. A sensitive element for use in color photography comprising a layerof emulsion sensitized to reddish light and a superposed layer' ofemulsion dyed with a solution containing approximately one-'half percent. uranine'-, one-tenth percent. eosine and fivehundredths per cent.xylene red.

37. An emulsion sensitive'to reddish light l and dyed with a dye whichfurther sensitizes to a colder color withoutsubstantially desensitizingto reddish light.

38. An emulsion sensltive to reddish light a-nd dyed with a dye'whichfurther sensitizes to a greenishy color without substantiallydesensitizing to reddish light. A' v 39. A photographic film for makingcolor pictures which comprises an emulsion hav- `mg one stratum which issensitive to a color to which another stratum on the entrant sideof saidfirst .stratum is substantially insensitive and the latter stratum beingsuiciently 40. A photographic film for making super-v posed complementalimages which comprises an' emulsion having different strata sensitive-to complemental colors, one stratum being suiiiciently absorptive ofcolors other than the color to which a succeeding stratum is sensitiveeffectively7 to restrict the exposure is sensitive.

5 of the latter stratum to the color to which it V7 41. A photographicfilm for making color pictures which comprises an emulsion havingsensitive and the latter stratum being 'sufiiciently absorptive ofcolder colors to cause said irst stratum to record an image of thereddish color aspect of an object field to which the emulsion is exposedfrom said entrant side.

' 42. A photographic film for making vsuperposed complemental imagesWhichcomprises an emulsion whosestrata are sensitive to complementalcolors, one stratum'being substantially insensitive to the complementalcolor to which a succeeding stratum is sensitive and being sufficientlyabsorptive ofA the complemental color to which it is sensitivesimultaneously to cause said strata res `ectively to record complementalimages 'o said color aspects of'an object field to which the emulsion isexposed-from the sideof the latter stratum.

43. A photographic film for making' superposed complemental images whichcomprises an emulsion having one stratum which is sensitive to a reddishcolor and another stratum which is sensitive to a complement'al colorbut relatively insensitive to the reddish color, the

latter stratum being suiciently absorptive of' said complement-al colorsimultaneouslyy to cause lsaid strata respectively to recordcomplemental images of said color aspects of an object eld to which theemulsion is exposed Efrom the side of the latter stratum.

v 44. A photographic film for making superposed complemental imageswhich comprises n emulsion having different strata Adierently sensitizedto complemental colors respectively. l

45. A photographic film for making superposed complemental imagescomprising an emulsion having different strata differently sensitized,one stratum. beingl sensitive to a greddish color and another stratumbeing sensitive to a complemental color.

46. A-photographic film for making vsuperi posed complemental imagescompusing an 4 emulsion havingdierenhstrata differently sensitized, anouter stratum being sensitiveto areddish color rand an inner stratumVbeing sensitive to a colder color.-

147.A photographic lm for making supergle emulsion coatingsubstantially/sensitizedv to one colorv only throughout a portion of itsdepth.

50. A photographic film'comprising a single emulsion coatingsubstantially sensitized to one color only throughout its outer stratum.

51. A photographic film comprising a 'single emulsion coatinsubstantially sensitized to reddish color 011 y throughout a'. portionof its depth.

52. A photographic film comprising asingle emulsion coatingsubstantially sensitized to reddish color only throughout its outerstratum. A

53. A photographic film for making color pictures which comprises asingle emulsion coating having one stratum which is sensitive to a colorto which another stratum on the entrant side of said first stratum issubstantially insensitive and the latter stratum being sufficientlyabsorptive of other colors substantially to restrict the exposure of thesaid first stratum to light of said first color.

54. A photographic film for making superposed complemental images whichcomprises a single emulsion coating having different strata sensitive tocomplemental colors, one stratum being sufficiently absorptive-of colorsother-than the color` to which a. succeeding stratum is sensitiveeffectively to restrict the exposure of the latterstratum tothe color towhich it is sensitive.

55. A photographic'film for making color pictures which comprises asingle, emulsion coating having one 'stratum which is sensitive to areddish color to which another stratum on the entrant side of said firststratum is substantially insensitive and the latter stratum beingsufi'iciently absorptive of colder colors to 'cause said first stratumto record an image-of the reddish color aspect of an Object field towhich the emulsion is exposed fromk 'said entrant side. e i

56. A photographic film for making superposed complemental imagesl whichcomprises va single emulsion coating whose strata are GQ sensitive tocomplemental colors, one stratum being substantially insensitive to thecomplemental color to which a succeedin stratum is sensitive and beingsufliciently a sorptive of the complemental color to which itissensitive simultaneously to .cause said strata. re-

spectively to record complemental images of said color aspects of anobject field to Which` the emulsion is exposed from the side of thelatter stratum.

= 57. A photographic film for making superposed complementalimages whichcomprises l a single" emulsion coating having one stratum .Which 1ssensitlve to a reddish color and another stratum Which 1s sensitlve to acomple- 4mental color but relatively insensitive .to thev reddish color,the latter stratum being sufficiently absorptive of said complementalcolor simultaneously to cause said strata respectively to recordcomplemental images of said color aspects of an object field to whichthe emulsion .is exposed from the side of the lat- Iter stratum.

58. A photographic film for making superposed complemental images whichcom rises a single emulsion coating having di erent strata differentlysensitized to complemental colors respectively.

59. A photographic film for making superposed complemental imagescomprising a single emulsion coating having different strata differentlysensitized, one stratum being sensitive to a reddish color and another`strat-um being sensitive to a complemental color.

60. A photographic Film for making superposed complemental imagescomprising a singlel emulsion coating having different stratadifferently sensitized, an outer stratum being sensitive to a reddishcolor and an inner stratum being sensitive to a colder color.

61.4 A photographic film for making superposed complemental imagescomprising' a single emulsion having different strata differentlysensitized,- an outer stratum being' sens1t1ve to a reddish color and aninner stratum being sensitive to a complemental color.

posed complemental images comprising a f single emulsion coating havingdifferent strata differently sensitized, one stratum being sensitive toa reddish color and another stratum being sensitive to a greenish color.

63. A color photographic-film or -plate bearing an emulsion sensitizedtorecord the color values of one portlon of the spectrum, sa1d emulsionbeing transparent to certaln of 4said color values and being treated torestrict the remainder of said color. values substantially to thesurface of the emulsion.

v 64. A color photographic film or plate comprising an emulsionsensitized to the orange red of the spectrum, a second emulsion sen'-sitized to the blue-green of the spectrum and colored yellow to therebydiminish the effect lof the blue-violet values upon the body of thesecond emulsion. i

65: Atcolor photographic film or plate coinprising an4emulsion'sensitized to the orange red ofthe spectrum, a second .emulsion4sensitized to the blue-green of the spectrum and having incorporatedthereinayellow dye for -the purpose of restricting the blue-violetrecord to the surface of the second emulsion, but permitting a greenrecord throughout the body of the said second emulsion.

. 66. A photographic film comprising a support carrying on one sidethereof strata of emulsions having different sensitivity for recordingdifferent color aspects of a scene in these strata respectively and anintermediate stratum having different characteristics. 67. Aphotographic film comprising a support carrying on. one side thereofstrata of emulsions having different sensitivity for recording differentcolor aspects of a scene in these strata respectively and anintermediate stratum which is relatively insensitive.

68. A photographic film comprising'a support carrying on one sidethereof three separatelyapplied layers, the first and last of saidlayers having different sensitivity for ref cording dierent coloraspects of a scene.

" absorptive of light of the color correspond-g 69. A'photographic filmcomprising a support carrying on one side thereof three separatelyapplied layers, the first and last of said layers having differentsensitivity for recording different color aspects of a scene and theintermediate layer comprising gelatine substantially free fromsensitivity.

70. A photographic film comprising asupport carrying on one side thereofthree strata for recording different color aspects in the first and laststrata respectively, and at least' one strat-um in advance of the laststratum being largely absorptive of light of the color corresponding tothe. record of the first stratum. ,v

71. A photographic film comprising a support carrying on one' sidethereof three sepa-- rately applied layers for` recording differentcolor aspects in the first and last layers respectively, and at leastone layer in 'advance vof the last layer being largely absorptive oflightof the color corresponding to the record of the first layer.

72. A photographic film comprising three.

strata of gelatine integrally throughout their transverse andlongitudinal coextents, the first and last strata being sensitized torecord different color aspects and one of the strata in advance of thelast stratum being largely inv to the recor o f the first stratum.

3. A photographic film comprising three separatelyapplied layers ofgelatine integrally united throughout their transverse .and longitudinalcoextents, the first and last layers being sensitized to recorddifferent color aspects,- and one of the layers in advance of the lastlay?? being largely .absorpti've'of light of the color corresponding tothe record of the first layer.

74. A photographic film comprising three strata of gela-tine integrallyunited throughout their transverse and longitudinal coexjof light tents,the first andlast strata being sensitized to record different coloraspects, and one of the strata in advance of the last stratum.

being largelyabsorptive of light of the color corresponding to therecord of the first stratum andthe absorptive stratum being relativelyinsensitive.

,. 75. A photographic film comprising three .separatelyapplied layersof-gelatine inteings 0f gelatine directly connected to each s' other,the first and last coatingsbeing sen- Sitized and one coating beinglargely ab` tized coatings are sensitive.

77. A photographic film comprising a support carrying on one sidethereof three strata integrally united throughout their transverse andlongitudinal extents, thelirst and last strat-a being sensitized and onestratum being largely absorptive o f light.

78. A transparent support having a photographic emulsion, the outersurface of said -sorptive of light to which both of the sensiemulsionbeing superficially dyed with a dil rect cotton dye.

tographic emulsion, the outer surfaceof said emulsion being dyed withCongo red.

80. 'A transparent support having1 tographic emulsion impregnated wit alight absorbing dye, and being superficially coated emulsion issensitive.

'79. A transparent support having a phoa pho- 4with a dye absorbent oflightto which said 181. A support having a photographic emulsionsensitive to a portion of the spectral range, a second support having apho-` tographic emulsion sensitive to another portion of the spectrum,said emulsions being placed in close contact between the twosupports,and the outer surface of one of said emulsions beingdyed with a dyeabsorbent to which the preceding emulsion is sensitive.

82. A support having a photographic emulsion sensitive to a portion -ofthe spectral range, a second support having a photographic emulsionsensitive to another portion of the spectrum, the outer surface of oneof sai-d emulsions being. dyed with Congo red,

said emulsions being placed in close between the two supports.

83. The method of making a s'ensltized elecomprises `forming a film andsensitizing different strata thereof to complementa] colors. 84. Themethod of making a sensitized elecontact ment for use in colorphotography which i ment for use in color photography which comprisesforming a ilm sensitlzing dierent Y strata thereof to complementalcolors, and

rendering the entrant stratum substantially absorptive of the color towhich it is seny sitive.

85. The methodof making a sensitized elevment for use in colorphotography `Which comprises forming a film, sensitizing differentstrata thereof to complemental colors, and rendering the entrant stratumsubstantially absorptive of the color to which it is'sensil tized, onestratum being sensitizedby ybathcomprises forming a film and'sensitizingdifg" ferent strata thereof to complemental colors, .one stratum beingsensitized before it is joined to another stratum and the other stratumbeing sensitized by bathing after the two strata have been joined.

88. The method of making a sensitized element for use in colorphotography which 'com rises coating a trans arentv su ort with a layerof emulsion,recoatingthesupport With another layer of emulsionpresensitized to reddish color, and then sensitizing the first emulsionto a greenish color. 89. The method of making a sensitized element foruse in vcolor photography which comprises coating a transparent supportwith a. layer of emulsion, recoating the support with another layer ofemulsion presensitlzed to reddish color, and then bathing the element ina dye, adaptedy to sensitize the first layer to a greenish colorWithout'desensitizing the second layer to the reddish color.

90.y The method of making a sensitized element for use in colorphotography which comprises coating a support with supe'rposed l strataof emulsion, sensitizing one'stratum .to one color, sensitizing'anotherstratum to another color, and staining the latter stratum to render itsubstantially opaque lto the color to which itI issensitized.

91. The method of making a sensitized element for use in colorphotography which' comprises coating a support with an emulsionsubstantially insensitive to light of certain color. recoating thesupport with an emulsion,

sensitizing the latter coating to' said color,

an-d dyeing the first'coating to render it sensitive and substantiallyopaque to another color.

92.` The method of making a sensitized ele- .ment for. use in colorphotography which.

comprises coating a support with an emulsion substantially insensitiveto light of certain color, recoating 'the ,support with an emulsion,sensitizing the latter coating to said 93. The method of making asensitized element comprising forming an' emulsionv Awhich is sensitiveto reddish light and imz -pregnating the emulsion with a dye whichfurther sensitizes toa colder color without substantially desensitizingto reddish light.

y 94. The method of maklng a sensitized element comprising forming anemulsion which is sensitive toreddish light Aand impregnating theemulsion with a dye which further sensitizes to a greenish colorlWithout substantially desensitizing to reddish light.

95. The'method of making a photographic film comprising forming a layerof emulslony which is predominantly transmissive to light 'of apredetermined color, and sensitizing the emulsion throughout a portionof its depth to approximately the same color. l

96. A photographic I4element lcomprising 4an image-bearing strip havinglatent complemental images at different ldeptlis therein. 97. Aphotographic element comprising an image-bearing strip having latentcomplemental images at different depths therein, 'one of the imagesbeing relatively lat compared .to another. l

98. A photographic element comprising an image-bearing strip havingil'atent complemental images at different ldepths therein, one oftheimages having negligible contrast compared to another.

99.-A A photographic element comprising an.

imagebearing strip having latent complemental images at different depthstherein,

the colder-color image being relatively flat compared to thewarmer-colei` image.

' 100. A hotographic element comprising an `imageearingstrip havinglatent substantially non-interpenetrati'ng images at different depthstherein.

101. A photographic element comprising an image-bearing strip' havinglatent substantially non-interpenetrating images at dii'erent depthstherein, oneof the images being relatively fiat compared to another.

- 10 2.A photographic element comprising an image-bearing strip havinglatent substantially Anon-interpenetrating images at different depthstherein, one of the images halying negligible'contrast compared to anoter.

v103. A photographic elementcomprising i an image-bearing strip havinglatent substanc tially non-interpenetrating complemental images atdifferent depths therein.

104. A photographic element comprising I an image-bearing strip havinglatent substantially non-interpenetrating complementalimages atdifferent depths therein, one of the images being relatively fiatcompared to another. 105. Aphotographic element comprising animage-bearing strip having latent substantially non-interpenetratingcomplemental images at different depths therein, one of the imy ageshaving negligible contrast compared to another.

106. Aphotographic element comprising .an

'image-bearing -strip having latent substantiallynon-interpenetrating'complemental images at different depths therein,the coldercolor image being relatively flat compared to the warmer-colorimage.

- 107.l A photographic element comprising a support .and a coating onthe support, the coating having at different depths therein latentimages corresponding to complemental color aspects.

108. A photographic element comprising a support and a coating on thesupport, the coating having at different depths therein latent imagescorresponding to complemental color aspects, one ofthe images beingrelatively flat compared to another.

109. A photographic element comprising a support and a coating on thesupport, th'e p coating having at different depths therein latent imagescorresponding to complemental color aspects, 'one of the images havingnegligible contrast compared to another.

110. A photographic element comprising a support and a coating on'thesupport, the

coating having at differentdepths therein latent images corresponding tocom lement-al color aspects, the colder-color image eing relatively flatAcompared to the Warmer-color image.

111. A photographic element comprising a support and a coating on thesupport, the coating having at different depths therein substantiallynon-interpenetrating latent images corresponding to complemental coloraspects.l

112. A photographic element comprising a support and a coating on thesupport, the coating having atl dierent depths therein substantiallynon-interpenetrating latent images corresponding to complemental coloraspects, one of the images being relatively fiat compared to another.

113. A photographic element comprising a support and a coating on thesupport, the coating having at different depths therein substantiallynon-interpenetrating latent images corresponding to complemental coloraspects, one of the images having negligible contrast compared toanother.

' 114.V A photographic element comprising a support and a coating on thesupport, the coating having at different depths therein substantiallynon-interpenetrating latent images corresponding to complemental coloraspects'. ,I

115. A photographic element comprising a f one of the images havinggelatine layer having superposed complementhe colder-color image'beingrelatively fiatcompared to the Warmer-color image.

119. A photographic element comprising a' gelatine layer havingsuperposed substantially non-interpenetratinglatent images in differentstrata thereof. f

120. A photographic element comprising a gelatine layer havingsuperposed substantially non-interpenetrating latent images in dierent'strata thereof, one of the images being relatively flat compared toanother 121. A photographic element comprising a gelatine layer havingsuperposed substantially 'non-interpenetrating latent images in.

differentv strata thereof, one of the images having negligible contrastcompared to another.v

122. A photographic element comprising agelatine layer having superposedsubstantially non-interpenetrating latent images iny different stratathereof, the images corresponding to complemental color aspects.

123. A photographic element comprising a gelatine layer havingsuperposed substantially non-interpenetrating latent images in dierentstrata thereof, the images corre sponding to complemental color aspects,one

to another.

124. A photo raphic element comprising a gelatine layer l(havingsuperposed substantially non-interpenetrating latent images in of theimages being relatively fiat compared different strata thereof, thevimages corresponding to complemental color aspects, and negligiblecontrast compared to another.

125. A photographic element comprising a gelatine layer havinglsuperposed substantially non-interpenetrating latent images in different-strata`thereof, the images corresponding to complemental color aspects..i

126. photographiefilm comprising a single emulsion containing insuccessive strata superposed -complemental `images based in the samedirection. Y l 127. A photographic'I film comprising a support and asingle emulsion coating onv one side of the support contalning 1nsuccessive strata a plurality of complemental images based toward thesupport.

the images being based in the 128. A photographic film comprising asin-4gle emulsion containing distinct images in successive stratarespectively, a'plurality of i p same direction. 129. A photographicfilm comprising a single emulsion containing distinct images insuccessive strata respectively,

the images being based toward the support.4

a plurality of I passing through the first image.

133. A emulsion containing complemental images in successive layers,oneimage being fiat relatively to the other image.

134. A photographic element comprising a lsupport and a plurality ofcoatings on the same side of the. support, two of said coatings havingtherein, respectively, non-interpenetrating latent images correspondingto complemental color aspects.

135. A photographic element comprising a support, and aplurality ofcoatings on the same side of the support, two of said coatings havingtherein, respectively, non-interpenetrating latent images correspondingto complemental color aspects and being separated by a third coating.

136. A photographic negative, comprising an imageearing strip havingcomplemental images therein at different depths.

137. A hotographic negative, comprising' an image-bearing strip havingsubstantially non-interpenetr'ating images therein at different depths.

` 138.V A photographic negative comprisingl an image-bearing striphaving substantially l a transparent support non-interpenetratingcomplemental images therein at different depths.

139. A photographic negative comprising and-a coating on the atransparent support having at different support, the coating depthstherein substantially non-interpenetrating images representingcomplemental color aspects.

140. A photographic negative comprising and a coating on the havingcomplemental support. the coating images therein at different depths,the image nearest the support bein'g relatively flat compared to anotherimage.

141. A photographic negative comprising a transparent support and acoating on the support, the coating having substantially"noninterpenetrating images therein at di photographic film comprising anferent depths, the image nearest the support'4 being relatively fiatcompared to lanother image. 4

142. A photographic negative comprising a transparent support and acoating `on the support, the coating havingsubstantially-noninterpenetrating complemental images there` in atdifferent depths, the image nearest the support being relatively flatcompared to an.

other image.

143. Aphotographic negative havingapluy of superposed developed images,one

rality of the images being substantially transparent. 144. Aphotographic negative having a vplurality of superposed developedcomple-` mental images, one of the images-being sub-V stantiallytransparent.

a transparent support, a coating on'the support having a plurality ofsuperposed vdeveloped images, the image next to the support beingsubstantially transparent.

149. A photographic negative comprising a transparent support, a coatingon the support having a plurality veloped images, the image next tothesupport representing the colder color and being substantiallytransparent.

150. A photographicA negative having a plurality of superposed developedimages on the same side o the support, one of the images beingconstituted by transparent silver salt.

151. A vphotographic negative having a plurality of mental images onthesame side of the support,

superposed developed compleof superposed deone of the images beingconstituted by trans. i

parent silver salt 152. VA photographic negative .having` a *..j-i.

plurality of superposed substantially non-1nterpenetrating developedimages on the same side of the support, one ofthe images beingconstituted by-transparent silver salt.

153. A photographic negative having a plurality of superposed developedimages on the same side of the support, the' image representing'th'ecolder color being constltutedl by transparent silver salt.

154. A photographicnegative comprlsing a transparent support, a coatingon the support having a plurality of superposed 'developed images, theimage next to the support being constituted by transparent silver salt.

155. yA photographic negative comprising images of a colored scene inrespective strata- `the component with which the veloped images,theimage next to the support representing the colder color beingconstitutedby transparent silver salt.

156.'.The method of producingmultiplex images which comprisessimultaneously Vforming different color-value images in successivestrata' of an emulsion by selective exposure to different colorcomponents of a polychromatic beam and obstructing the passage of anycomponent to a stratum nantly'exposed thereby.

157. The method of producing multiplex images which comprisessimultaneously forming two different color-valueimages in two successivestrata of anemulsion by selective exposure to two different colorcomponents of a polychromatic beam and with the first stratumsubstantially preventing the passage of first stratum is predominantlyexposed.

158. taneously forming, with a single polychromatic beam of light,different color-value images in successive strata of an emulsionsensitized to different color components of lightby selectivelyabsorbing, with certain of the strata, the color component to whicheach'such stratum is sensitive.

' 159. The method which comprises simul- `vtaneously formingI differentcolor-value of an emulsion with a single polychromatic 'beamv of lightby selectively absorbing and transmitting the color components of thelight in accor ance with the color sensitivity of the successive strata.

160. The method which ,comprises concomitantly formlng complementalimages respectively in successive strata of an emulsion by selectiveexposure to different color components of a polychromatic beam andabsorbl I yimg Certa'n of the components by the stratum selectivelyexposed thereby.

ll-. The method which comprises c on- ;comitantly forming twocomplemental images respectively in two successive strata of an emulsionby selective exposure to two different color components of apolychromatic beam and with the first stratum substantially preventingthe passage of the component with which the first stratum ispredominantly exposed.

. 162. The method of making superposed complemental images in a singleemulsion -which comprises forming the images in latent form in differentdepths of the emulsion recomitantly.

spectively, and developing the images con- 163. The method of makingsuperposed complemental images in a single emulsion which com vrisessimultaneously forming the` images atent form in different depths ofbeyond that predomi- The method whichV comprises simulvages recordingthe emulsion respectively, and developing the images concomitantly. -l164. The method. of making superposed' being restricted to a partialdepth of the emulsionby the light-retarding dye, and developing theimages concomitantly.` i

165. A method of producing a color photograph comprising forming inlayers of emulsion sensitized respectively to record different colorvalues, a plurality of superimposed latent images of different colorsensations, developing said latent images and coloring the images thusdeveloped respectively in colors other'than those'whose ,values are re-`corded in the said respective images. y 166. A method of producing acolor hotographcomprising forming in layers o emulsion sensitizedrespectively to record dift'era plurality of superimposed ent colorvalues, latent images of different color sensations, develo ing saidlatent images and coloring .each oi) the respective images thusdeveloped with a color whose values are recorded by another of' saidimages. v

167. The method of producing a color photograph in two colorscomprismgforming in layers of emulsion sensitized respectively to valuesand combined to record different color constitute a substantiallyunitary body, two

- superimposed latent images of different colon an'd a 4 then fixingsaid two images and then co oring` sensations, simultaneously developineach of said: images 4with that color whose .values are recorded by theother ima e.

of producing a co or pho- 168. The method tograph` which comprisesconcomitantly forming, in united layers of emulsion respectivelysensitized to record different color val-" ues, a plurality ofsuperposed latent images recording different color values.y 169. Themethodof producing color photograph which "comprises concomitantlyforming, in superposed strata of emulsion mounted on'the same side of asupport and sensitized to different color values-'respectively, aplurality of superposed latent images recording different color` values.

170. The method of producing a color l photograph which forming,in,.unite'd layers of emulsion respectively sensitized to recorddifferent color values, a pluralittiy of superposed latent imifi'erentcolor values, and concomitantly develo ing said images.

171. The method o producing a color photograph with 'a suitable supporthaving on one side layers of .emulsion sensitized respectively to recorddifferent colorvalues,` which comprises forming simultaneously in saldlayers of emulsion two ,latent images 13ecomprises concomitantlyv Cilimages in an emulsion sensitized to complementalcolors at diti'erentdepths, which comprises exposing the emulsion with light of thecomplemental colors, restricting to the first depth substantially alllight of the color to which it is sensitized, and transmitting to asucceeding depthl light of the color to which it is sensitized,'vvherebycomplemental im-` ages are formed in the respective depths.

173. The method of making a photographic element having images:1t-different depths which includes the step of treating the images witha developer having a high diffusion tendency and a low reduction po-ltential.

174. The method of making. a photo-Y graphic element having images atdifferent.

depths which includes the step of reducing the exhaustive ei'fect ofthel outer image on the inner image by the use of hydroquinone andbromide.

17 6. The method .of making a photographic element having images atdiierent depths which includes the step of reducing the exhaustiveeffect of the outer image on the inner image by the use of hydroquinoneand an alkaline carbonate and bromide.

177. The method of making a photo.- -graphic element having images atdiierent depths which includes swelling Vthe gelatine by introducing alliquid thereinto, and subsequently developing the images.

178. The 'method of making al photographic element having images atdifferent depths which includes swelling'the gelatine by introducing aliquid thereinto, and subsequently treating the images with a devel'-oper having a high diusiontendency' and a low reduction potential.

179. The' method. of making .a photographic element having imagesat'diiferent depths therein which' includes the step of ,fogging astratum of the emulsion before developingthe images.

.180. The method of making a photographic element having ima es atdiliaent depths therein which inclu es the step of fogging an innerstratum of the emulsion before developing the images.

181. The method of making a photographic element having images atdi'erent depths therein which includes the stepy of fogging and swellingthe gelatine before developin the images.

182. 'he method graphic element having images at dierent depths thereinwhich includes the step of fog-ging and swelling the gelatine and subofmaking a photosequently treating it with a developer vhaving a. highdiiusion tendency and a low reduction potential. l.

183. The method of producing la color photograph which comprisesconcomitantly forming, in united layers of emulsion respectivelysensitized to record dierent color values, a plurality of superposedlatent images recording different color values, and reproducing saidimages in united layers of emulsion respectively sensitized to recorddifferent color values. c

184. The method of producing a color photograph which comprisesconcomtantly forming, in united layers of 4emulsion respectivelysensitized to record .diii'erent color values, a plurality of superposedlatent images recording different color values, and reproducing saidimages Without separating saldlayers.

185. A method of producing a color photograph with a suitable supporthaving on one side layers of emulsion sensitized respectively to recorddiferent color values! which 4comprises forming simultaneously In saidtive from the negative thus formed.

186. The methodof producing a color photograph `With a suitable supporthaving on one side layers of emulsion sensitized respectively to recorddierent color values, which comprises forming in said layers of emulsiona lurality of superimposed imagesof` the ject photographed, each of saidimages recording a diierent color sensation,

individually coloring said images to' form a negative in diiierentcolors without 'disturbing the relative positions of said images in saidenulsion to thereby produce two superimposed images in different colorsin an emulsion on one side of saidsupport, printing from this negativein a. single operation a positive to form on said positive a `pl'uralityof superimposed latent images of different color sensations, andsubsequently developing and. coloring said positive.

187. The method of producing a color photograph with a suitable supporthaving on one side layers of emulsion sensitized respectively to recorddifferent color values, which comprises forming simultaneously saidlayers of emulsion a plurality of latent l images of different'colorsensations, developsubjected to a similar treatment to produce thelfinished picture.

188. -The method of producing a color` photograph with a suitablesupport having on one side layers of/emulsions sensitized respectivelyto record different color values, which comprises forming simultaneouslyin said layers of emulsion a plurality of latent images-of differentcolor sensations, subsequently developing and coloring the respectiveimages to form a negative, forming a` positive comprising a plurality ofcoatings sensitized respectively for colors complementary to the colorsemployed in the negative, printing the'positive in a single operation,and subsequently developing and toning the images formed on saidpositive.

189. The method of reproducing ilnages superposed on the sameside of asupport which comprises rendering one image relatively ineffective onprinting light and passing light through both images to print the otherimage.

190. The method of making color pictures which comprises separatelyprinting superposed complemental pictures, one image being printed bylight passing through the other image, and the latter image beingrendered relatively ineffective during the printing of the first image.

191. The method of separating superposed components of a representationof two color aspects ofv an object field on the same side of a supportwhich comprises printing one component by light passing through therepresentation of both fcolor aspects, the other component beingrendered substantially ineffective during the printing of the firstcomponent.

192. The method of separating superposed components of a representationoftwo color aspects of an object field which comprises printing onecomponent by light passing through the representation of both coloraspects of 'an' object field which comprises printing one component bylight passing through the representation of both color aspects, theother component being rendered substantially` ineffective during theprinting of the. first component, removing the first component, and thenrendering the second component effective and printing the same.

194. The method of making color pictures from superposed complementalimages which comprises printing one image without separating the images,and then removing the printed image and printing the other image.

195. The method of making color pictures from superposed complementalimages which comprises printing one image without separating the images,and then etching off the printed image and printing the other image.196. The method of making color pictures from superposed complementalsilver images which includes treating the images with a bleachcontaining a. reducer. y

197. The method of making color pictures from superposed complementalsilver images which includes treating the images with a A bleachcontaining an alkali sulphite.

198. The method of makingcolor pictures from superposed complementalsilver images which includes treatin the images with a,

'bleach acting with su cient rapidity substantially to prevent theimages from affecting each other.

199. The method of making color pictures from superposed complementalvsilver images which includes treatin .the lmages wlth a bleach to hardenthe ge atine throughout the which comprises printing oneimage, bleachingthe images, etching off. the printed image, and printing the otherimage.

202. The method of making color pictures from superposed complementalsilver images which comprises printing one image, bleaching the images,etching off the printed image, and then intensifying and printing theother image. f

203. The method of making color pictures from superposed complementalsilver images which comprises printing one image, bleaching the images,etching ofi' the printed image,

and then staining and print-ing thev other image.

204. The method of making color pictures from superposed complementalsilver images which comprises bleaclnng and separating the images, anddyeing one image with a dye having a heavy staining power.

205. The method of making color pictures from superposed complementalsilver images which comprises bleaching and separating the images, anddyeing one image with a dye having a heavy staining power and having aslow washing out rate.

206. The method of making color pictures from superposed complementalsilver images .which comprises printing one image, bleach'- ingandseparating the images, and dyeing one image with a dye having aheavy7 staining power.

207. The method'of making color pictures comprising simultaneouslyforming, by composite light, complemental images at different' depths inan emulsion ada ted to respond predominantly to different lightcomponents at different depths, and separately reproducin thecomplemental images Ain ldiie-rent coors. v

208. The method of making color ictures comprisin simultaneously.forming, y composite lig t, complemental images at different depths inan emulsion adapted to respond predominantly tov different lightcomponents at dili'erent depths, and separately `sus through the otherlayer, the image of' the other layer being. rendered substantially in-`effective during the printing of the first image.

210. The .methodof making color pictures l comprising exposing anemulsion having superposed strata sensitive to light components ofdifferent colors, simultaneously to form complemental ima es in therespective strata, andprinting the images to form complemental pictures,at least one image being printed without separating the layers.

211. The method of separating superposed components of a representationof two color aspects of an object field which comprises printing onecomponent by light passing through the 'representation' of both coloraspects, the other component being rendered substantially ineffectiveduring the printing of the .first component.

212. The method of making color pictures which comprisesforming a latentimage in one stratum of a sensitized emulsion, simultaneously forming arelatively thin complemental latent image in another stratum of theirstimage-by passing light through both images, lremoving the firstimage,'and printing the second image.

213. The method of making color pictures' lwhich comprisessimultaneously forming complemental latent images in different strata ofan emulsion by .exposing the emulsion through its transparent support,making `the first image nextv to the supportsubstantially negligible'compared to the. second f image, printing the second image by lightpassing through both images, removing the second image, and printing thelirst. image.

214. The methodof making color pictures Vwhich comprises formingsuperposed complemental silver images on the same side of a support,dyeing the images different colors. and then printing the imagesrespectivelyv with light of different colors.

215.. The method'of making color pictures comprising simultaneouslyforming, by composite light, complemental images at dierent depths in anemulsion adapted to respond vpredominantly to dierent light'componentsat different depths, and subsequently converting the respective imagesinto a composite color picture.

216. The method of vmaking 4color pictures comprising simultaneouslyforming complemental negatives at different depths lin an emulsion, andsubsequently producingi p ositives from the negatives, the production ofthe positives including passing a ,beam of light through 'the negativesin series. 217. The method. of makingcolor pictures which comprisesproducing at different depths in an emulsion superposed components of acolor representative of an object field,

and" subsequently reproducing the components by printing operationswhich include simultaneously passing a b'gam of light through all thecomponents.

218. The method of making color pictures Y which. comprisessimultaneously producing components of a color representation insuperposed layers of emulsion on the same side of a support. andsubsequently reproducing the components by printing operations whichinclude simultaneously passing a beam of light through all thecomponents,

219. The method of producing a` color photograph, comprising forming inlayers of emulsion on the same side of their support and sensitizedrespectively to record different color values a plurality -ofsuperimposed images of the 'subjectfpliotographem each of said imagesrecording aditferent color sensa-- tion, individually coloring saidimages. to-

form a negative in proper colors, printingfrom this negative in a singleoperation a positive to formen said positive 'a plurality ofsuperimposedflatent images of dili'erent color sensations, andsubsequently developing and coloring said positive. the emulsion,developing the images, printing As ideof their support and sensitizedrespectlvely to record different color values a-plurality 'of latentimages of different color sensations, developing .all of said latentimages,

supcessively coloring the respective images,

